#include <net/ip.h>
#include <net/tcp.h>
#include <net/route.h>
+#include <net/dst.h>
#include <linux/netfilter_ipv4/ip_tables.h>
#include <linux/netfilter_ipv4/ipt_REJECT.h>
#ifdef CONFIG_BRIDGE_NETFILTER
#define DEBUGP(format, args...)
#endif
-/* If the original packet is part of a connection, but the connection
- is not confirmed, our manufactured reply will not be associated
- with it, so we need to do this manually. */
-static void connection_attach(struct sk_buff *new_skb, struct nf_ct_info *nfct)
-{
- void (*attach)(struct sk_buff *, struct nf_ct_info *);
-
- /* Avoid module unload race with ip_ct_attach being NULLed out */
- if (nfct && (attach = ip_ct_attach) != NULL) {
- mb(); /* Just to be sure: must be read before executing this */
- attach(new_skb, nfct);
- }
-}
-
-static inline struct rtable *route_reverse(struct sk_buff *skb, int hook)
+static inline struct rtable *route_reverse(struct sk_buff *skb,
+ struct tcphdr *tcph, int hook)
{
struct iphdr *iph = skb->nh.iph;
struct dst_entry *odst;
dst_release(&rt->u.dst);
rt = (struct rtable *)skb->dst;
skb->dst = odst;
+
+ fl.nl_u.ip4_u.daddr = iph->saddr;
+ fl.nl_u.ip4_u.saddr = iph->daddr;
+ fl.nl_u.ip4_u.tos = RT_TOS(iph->tos);
}
if (rt->u.dst.error) {
dst_release(&rt->u.dst);
- rt = NULL;
+ return NULL;
}
+ fl.proto = IPPROTO_TCP;
+ fl.fl_ip_sport = tcph->dest;
+ fl.fl_ip_dport = tcph->source;
+
+ xfrm_lookup((struct dst_entry **)&rt, &fl, NULL, 0);
+
return rt;
}
static void send_reset(struct sk_buff *oldskb, int hook)
{
struct sk_buff *nskb;
- struct tcphdr otcph, *tcph;
+ struct iphdr *iph = oldskb->nh.iph;
+ struct tcphdr _otcph, *oth, *tcph;
struct rtable *rt;
u_int16_t tmp_port;
u_int32_t tmp_addr;
+ unsigned int tcplen;
int needs_ack;
int hh_len;
if (oldskb->nh.iph->frag_off & htons(IP_OFFSET))
return;
- if (skb_copy_bits(oldskb, oldskb->nh.iph->ihl*4,
- &otcph, sizeof(otcph)) < 0)
+ oth = skb_header_pointer(oldskb, oldskb->nh.iph->ihl * 4,
+ sizeof(_otcph), &_otcph);
+ if (oth == NULL)
return;
/* No RST for RST. */
- if (otcph.rst)
+ if (oth->rst)
+ return;
+
+ /* Check checksum */
+ tcplen = oldskb->len - iph->ihl * 4;
+ if (((hook != NF_IP_LOCAL_IN && oldskb->ip_summed != CHECKSUM_HW) ||
+ (hook == NF_IP_LOCAL_IN &&
+ oldskb->ip_summed != CHECKSUM_UNNECESSARY)) &&
+ csum_tcpudp_magic(iph->saddr, iph->daddr, tcplen, IPPROTO_TCP,
+ oldskb->ip_summed == CHECKSUM_HW ? oldskb->csum :
+ skb_checksum(oldskb, iph->ihl * 4, tcplen, 0)))
return;
- /* FIXME: Check checksum --RR */
- if ((rt = route_reverse(oldskb, hook)) == NULL)
+ if ((rt = route_reverse(oldskb, oth, hook)) == NULL)
return;
hh_len = LL_RESERVED_SPACE(rt->u.dst.dev);
nskb->dst = &rt->u.dst;
/* This packet will not be the same as the other: clear nf fields */
- nf_conntrack_put(nskb->nfct);
- nskb->nfct = NULL;
- nskb->nfcache = 0;
-#ifdef CONFIG_NETFILTER_DEBUG
- nskb->nf_debug = 0;
-#endif
+ nf_reset(nskb);
nskb->nfmark = 0;
#ifdef CONFIG_BRIDGE_NETFILTER
nf_bridge_put(nskb->nf_bridge);
if (tcph->ack) {
needs_ack = 0;
- tcph->seq = otcph.ack_seq;
+ tcph->seq = oth->ack_seq;
tcph->ack_seq = 0;
} else {
needs_ack = 1;
- tcph->ack_seq = htonl(ntohl(otcph.seq) + otcph.syn + otcph.fin
+ tcph->ack_seq = htonl(ntohl(oth->seq) + oth->syn + oth->fin
+ oldskb->len - oldskb->nh.iph->ihl*4
- - (otcph.doff<<2));
+ - (oth->doff<<2));
tcph->seq = 0;
}
sizeof(struct tcphdr), 0));
/* Adjust IP TTL, DF */
- nskb->nh.iph->ttl = MAXTTL;
+ nskb->nh.iph->ttl = dst_metric(nskb->dst, RTAX_HOPLIMIT);
/* Set DF, id = 0 */
nskb->nh.iph->frag_off = htons(IP_DF);
nskb->nh.iph->id = 0;
nskb->nh.iph->ihl);
/* "Never happens" */
- if (nskb->len > dst_pmtu(nskb->dst))
+ if (nskb->len > dst_mtu(nskb->dst))
goto free_nskb;
- connection_attach(nskb, oldskb->nfct);
+ nf_ct_attach(nskb, oldskb);
NF_HOOK(PF_INET, NF_IP_LOCAL_OUT, nskb, NULL, nskb->dst->dev,
- ip_finish_output);
+ dst_output);
return;
free_nskb:
kfree_skb(nskb);
}
-static void send_unreach(struct sk_buff *skb_in, int code)
+static inline void send_unreach(struct sk_buff *skb_in, int code)
{
- struct iphdr *iph;
- struct udphdr *udph;
- struct icmphdr *icmph;
- struct sk_buff *nskb;
- u32 saddr;
- u8 tos;
- int hh_len, length;
- struct rtable *rt = (struct rtable*)skb_in->dst;
- unsigned char *data;
-
- if (!rt)
- return;
-
- /* FIXME: Use sysctl number. --RR */
- if (!xrlim_allow(&rt->u.dst, 1*HZ))
- return;
-
- iph = skb_in->nh.iph;
-
- /* No replies to physical multicast/broadcast */
- if (skb_in->pkt_type!=PACKET_HOST)
- return;
-
- /* Now check at the protocol level */
- if (rt->rt_flags&(RTCF_BROADCAST|RTCF_MULTICAST))
- return;
-
- /* Only reply to fragment 0. */
- if (iph->frag_off&htons(IP_OFFSET))
- return;
-
- /* Ensure we have at least 8 bytes of proto header. */
- if (skb_in->len < skb_in->nh.iph->ihl*4 + 8)
- return;
-
- /* if UDP checksum is set, verify it's correct */
- if (iph->protocol == IPPROTO_UDP
- && skb_in->tail-(u8*)iph >= sizeof(struct udphdr)) {
- int datalen = skb_in->len - (iph->ihl<<2);
- udph = (struct udphdr *)((char *)iph + (iph->ihl<<2));
- if (udph->check
- && csum_tcpudp_magic(iph->saddr, iph->daddr,
- datalen, IPPROTO_UDP,
- csum_partial((char *)udph, datalen,
- 0)) != 0)
- return;
- }
-
- /* If we send an ICMP error to an ICMP error a mess would result.. */
- if (iph->protocol == IPPROTO_ICMP
- && skb_in->tail-(u8*)iph >= sizeof(struct icmphdr)) {
- icmph = (struct icmphdr *)((char *)iph + (iph->ihl<<2));
-
- if (skb_copy_bits(skb_in, skb_in->nh.iph->ihl*4,
- icmph, sizeof(*icmph)) < 0)
- return;
-
- /* Between echo-reply (0) and timestamp (13),
- everything except echo-request (8) is an error.
- Also, anything greater than NR_ICMP_TYPES is
- unknown, and hence should be treated as an error... */
- if ((icmph->type < ICMP_TIMESTAMP
- && icmph->type != ICMP_ECHOREPLY
- && icmph->type != ICMP_ECHO)
- || icmph->type > NR_ICMP_TYPES)
- return;
- }
-
- saddr = iph->daddr;
- if (!(rt->rt_flags & RTCF_LOCAL))
- saddr = 0;
-
- tos = (iph->tos & IPTOS_TOS_MASK) | IPTOS_PREC_INTERNETCONTROL;
-
- {
- struct flowi fl = { .nl_u = { .ip4_u =
- { .daddr = skb_in->nh.iph->saddr,
- .saddr = saddr,
- .tos = RT_TOS(tos) } } };
- if (ip_route_output_key(&rt, &fl))
- return;
- }
- /* RFC says return as much as we can without exceeding 576 bytes. */
- length = skb_in->len + sizeof(struct iphdr) + sizeof(struct icmphdr);
-
- if (length > dst_pmtu(&rt->u.dst))
- length = dst_pmtu(&rt->u.dst);
- if (length > 576)
- length = 576;
-
- hh_len = LL_RESERVED_SPACE(rt->u.dst.dev);
-
- nskb = alloc_skb(hh_len + length, GFP_ATOMIC);
- if (!nskb) {
- ip_rt_put(rt);
- return;
- }
-
- nskb->priority = 0;
- nskb->dst = &rt->u.dst;
- skb_reserve(nskb, hh_len);
-
- /* Set up IP header */
- iph = nskb->nh.iph
- = (struct iphdr *)skb_put(nskb, sizeof(struct iphdr));
- iph->version=4;
- iph->ihl=5;
- iph->tos=tos;
- iph->tot_len = htons(length);
-
- /* PMTU discovery never applies to ICMP packets. */
- iph->frag_off = 0;
-
- iph->ttl = MAXTTL;
- ip_select_ident(iph, &rt->u.dst, NULL);
- iph->protocol=IPPROTO_ICMP;
- iph->saddr=rt->rt_src;
- iph->daddr=rt->rt_dst;
- iph->check=0;
- iph->check = ip_fast_csum((unsigned char *)iph, iph->ihl);
-
- /* Set up ICMP header. */
- icmph = nskb->h.icmph
- = (struct icmphdr *)skb_put(nskb, sizeof(struct icmphdr));
- icmph->type = ICMP_DEST_UNREACH;
- icmph->code = code;
- icmph->un.gateway = 0;
- icmph->checksum = 0;
-
- /* Copy as much of original packet as will fit */
- data = skb_put(nskb,
- length - sizeof(struct iphdr) - sizeof(struct icmphdr));
-
- skb_copy_bits(skb_in, 0, data,
- length - sizeof(struct iphdr) - sizeof(struct icmphdr));
-
- icmph->checksum = ip_compute_csum((unsigned char *)icmph,
- length - sizeof(struct iphdr));
-
- connection_attach(nskb, skb_in->nfct);
-
- NF_HOOK(PF_INET, NF_IP_LOCAL_OUT, nskb, NULL, nskb->dst->dev,
- ip_finish_output);
+ icmp_send(skb_in, ICMP_DEST_UNREACH, code, 0);
}
static unsigned int reject(struct sk_buff **pskb,
}
static int check(const char *tablename,
- const struct ipt_entry *e,
+ const void *e_void,
void *targinfo,
unsigned int targinfosize,
unsigned int hook_mask)
{
const struct ipt_reject_info *rejinfo = targinfo;
+ const struct ipt_entry *e = e_void;
if (targinfosize != IPT_ALIGN(sizeof(struct ipt_reject_info))) {
DEBUGP("REJECT: targinfosize %u != 0\n", targinfosize);
git://git.onelab.eu / linux-2.6.git / blobdiff